From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id 4231129DF9 for ; Wed, 3 Feb 2016 16:22:38 -0600 (CST) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay2.corp.sgi.com (Postfix) with ESMTP id 3090A304039 for ; Wed, 3 Feb 2016 14:22:35 -0800 (PST) Received: from ipmail07.adl2.internode.on.net (ipmail07.adl2.internode.on.net [150.101.137.131]) by cuda.sgi.com with ESMTP id ysgJqIVX8KKFVN78 for ; Wed, 03 Feb 2016 14:22:30 -0800 (PST) Date: Thu, 4 Feb 2016 09:22:16 +1100 From: Dave Chinner Subject: Re: stop using ioends for direct write completions Message-ID: <20160203222216.GG459@dastard> References: <1452766237-2314-1-git-send-email-hch@lst.de> <20160128131656.GB14876@infradead.org> <20160129141232.GA43184@bfoster.bfoster> <20160202112046.GB28777@lst.de> <20160202153117.GB1853@bfoster.bfoster> <20160202164237.GA25436@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20160202164237.GA25436@lst.de> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Christoph Hellwig Cc: Brian Foster , xfs@oss.sgi.com, darrick.wong@oracle.com On Tue, Feb 02, 2016 at 05:42:37PM +0100, Christoph Hellwig wrote: > On Tue, Feb 02, 2016 at 10:31:18AM -0500, Brian Foster wrote: > > FWIW, I don't see any such review comments against the three versions of > > the "DIO needs an ioend for writes" patch I have in my mailbox, but I > > easily could have missed something..? But if there wasn't time, then > > fair enough. > > I'll have to look at the mailboxes, but I remember Dave sending this > out and complaining. I don't recall the exact discussion that was had, but at the time it was an evil that I couldn't see a way of avoiding, and with no other solution being presented. ISTR a tie-in with the DAX code, too, but that's gone away now with the block zeroing during allocation rather than using unwritten extents and completions for this. > > If COW is the primary motivator, perhaps we can bundle it with that > > work? > > The prime motivator is to: > > (1) avoid a pointless memory allocation > (2) avoid a pointless context switch > (3) avoid pointless code complexity > > COW is just another case where these show up. *nod* Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs